The present invention relates to speed reduction devices and, more particularly, to speed reduction devices for use with powered multi-purpose woodworking tools.
Multi-purpose woodworking tools typically include a frame, a pair of parallel way tubes extending along a longitudinal dimension of the frame, and a headstock mounted for slidable adjustment on the way tubes. The headstock includes a motor and power transmission system having an output spindle. The output spindle of the headstock may drive various woodworking tools such as tablesaws, lathes, shapers, disc sanders, jointers, bandsaws and the like, which are mounted on the way tubes.
An example of a typical multi-purpose woodworking tool is shown in U.S. Pat. No. 3,282,309 to Parker et al in which a variety of woodworking tools may be powered directly by the output spindle of the headstock of the machine. The headstock is typically provided with means for varying the speed of the output spindle to accommodate the requirements of the particular tool being used. Thus, a higher spindle speed may be used for operations such as sawing and a slower spindle speed may be used for operations such as lathe turning. While such an arrangement is acceptable for many woodworking operations, the lowest spindle speed available is often too high for faceplate turning operations involving large diameter workpieces such as plates and bowls.
Devices which are designed exclusively for lathe turning are typically provided with a series of shafts and interconnecting belts as shown in U.S. Pat. No. 2,103,464 to Judelshon and U.S. Pat. No. 2,394,209 to Scuse. These two patents disclose devices in which an intermediate shaft is driven through a belt by a motor and the intermediate shaft drives an output shaft at a lower speed than the motor output shaft speed. Both of these machines require a great deal of space and are not readily adaptable for use with a multi-purpose woodworking tool such as the one shown by Parker et al.
Consequently, there is a need for a speed reduction device which may be attached to an existing powered woodworking tool having a headstock mounted on a pair of parallel way bars such that the output speed of the speed reduction device is sufficiently low to permit faceplate turning operations to be performed with large diameter workpieces.
In addition, a speed reduction device is needed which is compact enough to be supported by the way bars of a multi-purpose woodworking tool and which has an output shaft located at the same height as the output spindle of the headstock.